Endovascular surgery involves the placement of stents or stent grafts into the vasculature of a patient and in one form is particularly directed to the deployment of stent grafts into vessels of the body to span or bridge a defect in the vasculature. Such a defect can for instance be an aneurysm where part of the wall of the vessel has weakened and the vessel has expanded in that region. Placement of endovascular stent grafts in such regions requires a stable landing zone for proximal and distal ends of a stent graft so that the stent graft engages securely against the wall of the vessel preventing migration of the stent graft and endoleaks around the stent graft. Such endoleaks can exacerbate an aneurysm problem.
In some regions of the vasculature, especially in the proximity of essential vessels such as near the renal arteries, often there is only a relatively short landing zone for the proximal end of a stent graft and this can require that a stent graft should extend beyond the renal arteries which requires branch grafting or fenestrations to allow access to the renal arteries. Such a problem could be avoided if a stable landing zone was provided in a juxta-renal position such as just below the renal arteries.
It is the object of this invention to provide a device which can improve the chance of providing a successful landing zone for a stent graft or at least provide a physician with a useful alternative.
Throughout this specification the term distal with respect to a portion of the aorta, a deployment device or a prosthesis means the end of the aorta, deployment device or prosthesis further away in the direction of blood flow away from the heart and the term proximal means the portion of the aorta, deployment device or end of the prosthesis nearer to the heart. When applied to other vessels similar terms such as caudal and cranial should be understood.